In retail stores such as supermarkets, a device such as a point-of-sale (POS) register (i.e. a cash register) is used to register and checkout commodities purchased by customers visiting the store. The POS register is usually operated by a store employee who registers and checks out the commodities by using a barcode scanner connected to the POS register to read barcodes appended to the commodities.
Recently, there are proposals for a commodity sale processing system known as a self-checkout system, where customers visiting the store themselves read the barcodes, thereby preventing crowding at the register during busy hours and reducing the workload on the store (e.g. Japanese Unexamined Patent Application, First Publication No. H6-243340).
According to Japanese Unexamined Patent Application, First Publication No. H6-243340, a customer who has selected commodities for purchase goes to a place where a self-checkout system is installed, uses a scanner of the system to read a barcode appended to the commodity, and deposits the commodity whose barcode was read on a belt conveyor of the system. The barcode of the deposited commodity is read again while it is being conveyed. In the self-checkout system according to Japanese Unexamined Patent Application, First Publication No. H6-243340, when the barcode read by an operation performed by the customer and the barcode read while being conveyed on the belt conveyor match, commodity registration is deemed legitimate, whereas when they do not match, a process is executed for prompting the customer to read the barcode again.
However, Japanese Unexamined Patent Application, First Publication No. H6-243340 reveals a problem that confirming all commodities purchases is time consuming. While one conceivable method of reducing checkout time is to delete the process of confirming commodity purchases, when customers themselves are registering commodities, an opportunity is needed to restrict incorrect registrations. Another problem of self-checkout systems such as that described in Japanese Unexamined Patent Application, First Publication No. H6-243340 is that they are not easy to install, since they require large equipment including carrying devices.